How to use RSYNC to make backups of your data.

Practical Application of RSYNC

For High Availability Mission Critical Environments

RSYNC- copies files and folders to or from a local and or network destination and is considered the “swiss army knife” of the file replication world.  The purpose of the document is to prove a practical approach to the use of rsync – everyday use.  Any one of us can read a man page and this paper is not intended as such.

The following is a breakdown of the most common switches and syntax that I have found useful for performing quick backups.

Most common switches:
  • -u                                             copy only updated or changed files (must be first option)
  • -ah                                          always add this switch
  • –progress                          gives verbose output
  • –delete                               remove files at the destination that aren’t in the source
  • –compress-level=0     provide no compression
  • –inplace                             create files and folders respectively

Lastly, include the source and then the destination, always include the source first followed by a white space and then the destination.  Here’s what a pretty basic backup command looks like:

rsync -ah –progress –delete –compress-level=0 –inplace /source /destination

Additional notes and advanced application:

Copying server to server:

(arguments always given for path in *SOURCE* -> *DESTINATION* format)

rsync -ah -e ssh –progress –delete –compress-level=0 –inplace /source root@192.168.*.*:/destination/folder

Use switch -u to copy only files that have been updated or changed, this option *MUST* be the first one declared

rsync -u -ah -e ssh –progress –delete –compress-level=0 –inplace /source root@192.168.*.*:/destination/folder

An extremely useful option to invoke is bwlimit which is used to limit the bandwidth use…

–bwlimit=5000

The number is interpreted as kb/sec and the option must the last option called before the source and the destination and entered.

rsync -u -ah -e ssh –progress –delete –compress-level=0 –inplace –bwlimit=1000 vgizzi@192.168.60.38:/home/vgizzi/origbackup/* ~

SPECIAL NOTES ON SYNCING BETWEEN
A SYNOLOGY RACKSTATION AND A FREENAS APPLIANCE

Anyone who has used a Synology Rackstation has undoubtedly become familiar with more than one or two quirks.  Use the following code to get rsync copying to a FreeNAS appliance correctly.  Had I made the decision originally, I would have saved the money spent on the Synology and bought two Dell PowerEdge C2100 servers and threw FreeNAS on them.

On the Synology

cd /usr/syno/bin/

chmod root:root rsync

cd /

cd usr

mkdir /usr/local/

cd local

mkdir /usr/local/bin/

cd bin

ln -s /usr/syno/bin/rsync /usr/local/bin/rsync

On the FreeNAS

cd /usr/local/bin/

chmod root:wheel rsync

cd /

cd usr

mkdir /usr/syno/

cd syno

mkdir /usr/syno/bin/

cd bin

ln -s /usr/local/bin/rsync /usr/syno/bin/rsync

I had to sync from the Synology to the FreeNAS because of rsync protocol data-stream errors (presumably because FreeNAS root group is set to wheel and root as an auxiliary group)  I don’t believe this will be an issue when going from FreeNAS to FreeNAS as both will be set to wheel.

Additional options:
  • -t            Preserve date and time stamps
  • –perms        Preserve file permissions (or attempt to at least)

RSYNC in its final form!

rsync –rsync-path=/usr/syno/bin/rsync -u -a -h -e ssh -r -l -t –no-p –no-g –progress –delete –compress-level=0 –inplace –bwlimit=5000 /volume1/hdswork/* root@192.168.63.30:/mnt/SHARES

This script can also be used to back up local files as well

Leave a Reply

Your email address will not be published. Required fields are marked *